Dr. Kate Shannon of the Vancouver-based B.C. Centre for Excellence in HIV/AIDS said the Conservative government chose to ignore research that shows criminalizing any aspect of prostitution puts sex workers at risk.

"The (Supreme Court of Canada) decision was clear that the previous laws put sex workers at risk in multiple ways: by isolating sex workers, reducing their ability to negotiate transactions, reducing their access to indoor spaces," Shannon, who is the Director of the centre's Gender and Sexual Health Initiative, said in an interview.

"This not only ignores that, but it goes one step further in criminalizing the purchase of sex. There's a huge concern that we're going to see rates of violence and other risks go up rather than down."

Shannon said Canada should follow the example of Australia and New Zealand, which have decriminalized sex work. Those countries, she said, haven't seen an increase in sex work or violence.

"I think it's clearly ideologically driven," she said.

"A lot of evidence was not discussed (by the federal government) or thrown out."